Health: 'Are probiotics as friendly as they're made out to be?"

There are so many contradictory claims, you'd be right to be confused.

According to the World Health Organisation probiotics, meaning "for life", are "live microorganisms (such as bacteria and yeast), which when administered in adequate amounts, confer a health benefit on the host".

Put in more human terms, they are the "good" strains of gut bacteria that can be helpful to digestion and our immune system.

Nearly 60 per cent of UK households buy probiotic drinks, supplements and yoghurts on a regular basis and in recent years there has been a slew of studies showing their health benefits, admittedly in many cases from the companies that manufacture them. Yet some products have also been criticised.

Last year, scientists at the European Food Safety Agency (EFSA) threw out 180 health claims made about probiotics – including those as vague as "maintains digestive comfort" and "boosts defences" – because there simply wasn't enough evidence for them to be substantiated.

However, Sarah Stelling, of the Edinburgh Centre of Nutrition and Therapy, believes probiotics can play a key role in a healthy diet. "It's true that not all products will be as good as others but there's convincing evidence that the right products will do us good," she says. "They can be a wonderful way to prime the immune system and can act as a protective layer against bad bacteria which can cause illness, which is why it makes sense to take a daily supplement or work something into your everyday diet."

Indeed, she believes the benefits go even further. "The right probiotics can help people who are travelling abroad and coming into contact with different bugs that might upset their system," she says.

"They will also help anyone taking antibiotics, which kill good bacteria as well as bad, or people going into hospital where gut infections are rife. As well as being useful in minimising the effects of stomach problems, there is also evidence that probiotics can help with conditions like eczema and hay-fever, as well as many others.

"If you are interested in finding out whether you might benefit from a probiotic supplement," she says, "it might be worth considering having digestive gut analysis done. This will show up exactly what bacteria is present and, equally importantly, what is not."

In addition to the everyday health benefits, there is evidence that elderly people in particular may benefit from taking probiotics. Dr Sandra McFarlane, from the microbiology and gut biology group at the University of Dundee, has said that as people grow older they have reduced levels of friendly bacteria and increased levels of disease-causing bacteria, leaving them more vulnerable.

She added that they were also more susceptible to gastrointestinal infections and bowel conditions such as IBS, something the right probiotic supplement could protect against. It is perhaps worth noting that the 21 people who died in an E.coli outbreak in Lanarkshire, Scotland, in 1996, were all elderly.

Professor Christine Edwards, head of human nutrition at the University of Glasgow, believes that with unreliable products still on the market, the onus must be on consumer to check the ones they are using are beneficial.

"While the larger manufacturers such as Nestle, Danone and Yakult make products that are effective, there are other smaller brands that are not," she says. "It is important they contain the correct strain of live bacteria, and you don't need to be a scientist to do this.

Generally, if a product lists the bacteria it contains and doesn't just say 'probiotic' on it, you can assume it is reliable. It's a simple check anyone can do at the supermarket. But you can also write down the names of the different bacteria then go and look them up afterwards if you are interested in finding out more about how the separate bacteria might be able to help you."

As well as checking that a product contains the correct strain of live bacteria – according to the experts a blend of bifidobacteria or lactobacilli – consumers should also look for evidence that it contains at least ten million bacterium, as anything less will be unlikely to survive its shelf life. If the label does not specify these details, the manufacturer should be able to help.

For Prof Edwards, the future lies not just in probiotics, but in their lesser known, but apparently cleverer little sister, the prebiotic. While probiotics introduce or top up the "good" bacteria in the gut, prebiotics feed the growth or development of beneficial micro- organisms already there, offering a raft of scientific possibilities.

"With more research we can investigate the ways in which prebiotics and probiotics can be used together. At the moment we have no idea what the limits might be. There may be the potential to use gut bacteria in treating and preventing a raft of serious conditions."

www.ecnt.co.uk

This article was first published in Scotland On Sunday, 17 October, 2010